Plays the Final Fantasy II Theme. Requires https://github.com/gleitz/midi-js-soundfonts to be installed into the same directory.

play.js

var playSound = require('play-sound');
var path = require('path');
var _ = require('lodash');
var player = playSound();

var chords = [
  ['c3', 'd3', 'e3', 'g3'],
  ['a2', 'b2', 'c3', 'e3'],
  ['c3', 'd3', 'e3', 'g3'],
  ['a2', 'b2', 'c3', 'e3'],
  ['a2', 'c3', 'f3', 'g3'],
  ['b2', 'd3', 'g3', 'a3'],
  ['ab2', 'c3', 'eb3', 'g3'],
  ['bb2', 'd3', 'f3', 'a3']
];

var notes = _.flatten(chords.map(function(chord) {
  var chordDown = [octaveUp(1)(chord[0]), chord[3], chord[2], chord[1]];
  return chord
    .concat(chord.map(octaveUp(1)))
    .concat(chord.map(octaveUp(2)))
    .concat(chord.map(octaveUp(3)))
    .concat(chordDown.map(octaveUp(3)))
    .concat(chordDown.map(octaveUp(2)))
    .concat(chordDown.map(octaveUp(1)))
    .concat(chordDown);
}));

notes = notes.concat(notes).concat(notes);

var i = 0;
function nextNote() {
  var note = notes[i++];
  if (!note) return;
  play(note);
  setTimeout(nextNote, 150);
}
nextNote();

function octaveUp(n) {
  return function(note) {
    var num = Number(note[note.length - 1]);
    return note.substring(0, note.length - 1) + (num + n);
  }
}

function play(note) {
  player.play(path.resolve('midi-js-soundfonts/FluidR3_GM/celesta-mp3/' + note.toUpperCase() + '.mp3'));
}